[meteorite-list] Meteorites - warm or hot to the touch?

[Chris Peterson]

Hi Elton-

I'm curious about the basis of your assertion that physics suggests a 
typical meteorite should be hot on the outside and cool on the inside. I 
would expect a large stone (or iron) to have an internal temperature similar 
to what it was at in space, which can vary from around -100°C to +60°C 
depending on the parent's albedo and surface properties. As the object gets 
smaller, its passage through the atmosphere becomes more important in 
determining its final temperature. Something fist sized, for instance, will 
have probably equilibrated its temperature to the atmosphere during most of 
its fall (-40°C is a good value for this), and then begun warming from the 
outside during the last minute in warmer air. Depending on the thermal 
conductivity of the material, I think it will feel somewhere between ambient 
and slightly cool. I believe that the conditions leading to a warm or hot 
exterior are not common.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "E. L. Jones" <jonee at epix.net>
To: <Meteorite-list at meteoritecentral.com>
Cc: "AL Mitterling" <almitt at kconline.com>
Sent: Sunday, July 03, 2005 5:42 PM
Subject: Re: [meteorite-list] Meteorites - warm or hot to the touch?


> I personally believe the meteorite surface is very warm slightly hot on 
> most falls while the interior is very cold.  That is what the physics say 
> should be.  While metal/iron is a good heat conductor, olivine/silicates 
> is/are not, and it should take a longer  time for the two temperature 
> extremes to neutralize in a stony fall. Ironically, an iron might actually 
> take longer to cool down than a stone becasue it could theoretically store 
> up more of the ablation heat internally than a stony could.